Case Head Issue or Die Marks?

[gasrat]

I’ve got a question about these cases. All brass is Lapua SRP and has been loaded 8-9 times with mild loads of 6.5. All sizing has always been two thou shoulder bump using a Redding Type S die. Ran through Sinclair Mandrel and seated with Forester Micro. Anneal is every firing or two. Again, loads have always been normal, with no hot loads.

I’ve taken a pick and checked the inside of the cases for any felt issues as well as looked inside the cases with my bore scope, which turned up nothing that I could see. The discoloration cannot be felt on the cases. There is others like these, but these are the ones I found first in the batch.

I’m leaning towards the marks being made by the sizing die versus case head issue, but want a second opinion. Brass grows 5-6 thou when fired in chamber.

Any responses is appreciated. Thanks

 

[Cascade Hemi]

It's normal, the case head web expands less than the case body and what you're seeing is the die sizing the body without touching the case head.

 

[Steel head]

Normal

 

[gasrat]

Thanks….Appreciate the responses.